Floristic Quality Index of Pleasant Valley Conservancy

Botanists and plant ecologists sometimes use a quantitative measure called the Floristic Quality Index (FQI) to express the "quality" of a natural area. This standardized tool, introduced by Floyd Swink and Gerald Wilhelm of the Morton Arboretum, replaces subjective assessments, and although approximate, provides a useful number for comparing various natural areas. FQI is not a stand-alone value, but is used together with other assessments to evaluate the quality of a site.

See 13-year FQI averages for all PVC management units at this link

Coefficient of Conservatism The basis of the FQI calculation is the coefficient of conservatism (C), a value given to each species on a state-wide basis. Each native species is assigned a value from 0 to 10, that represents the probability that this plant species is likely to occur in landscapes relatively unaltered from those of pre-settlement times. Plant species with high C values are relatively specialized in their requirements, and thus are found in more restricted habitats.

Thus, a widespread species such as Canada goldenrod (Solidago canadensis), found in numerous habitats from roadsides to remnant prairies, is assigned a value of 1 whereas prairie dropseed (Sporobolus heterolepis), found almost exclusively on high-quality remnant prairies, has a value of 10.

The C values for northern Illinois are given in the important book by Swink and Wilhelm Plants of the Chicago Area (published by the Indiana Academy of Sciences). A similar set of C values has been established for all members of the Wisconsin flora, and has been published by the Wisconsin Department of Natural Areas. The C value for each native species is also given on the University of Wisconsin-Madison Herbarium web site and in Wildflowers of Wisconsin and the Upper Midwest, by Merel Black and Emmet J. Judziewicz, University of Wisconsin Press, Madison, Wisconsin.

The mean C for Pleasant Valley Conservancy was calculated from a detailed check list which combines all our observations for the 4 years 2002 through 2005. This check list has a total of 319 native species (out of a total of 401 identified species), found in the various habitats (oak woods, oak savanna, marsh, prairie remnant, etc.).

Some examples of species at Pleasant Valley with high C values are: Lithospermum canescens (hoary puccoon), Panicum leibergii (prairie panic grass), and Sporobolus heterolepis (prairie dropseed), C=10; Asclepias purpurascens, Asclepias viridiflora, Ceanothus americanus, Cypripedium parviflorus, Eupatorium sessilifolium, and Viola pedatifida, C=9, Aster sericeus, Baptisia alba, Bromus kalmii, Hasteola suaveolens, Lithospermum incisum, Oxalis violacea, and Pedicularis lanceolata, C=8. In total, there are 190 species at Pleasant Valley Conservancy which have C values of 5 or higher.

Follow this link for the C value for each species at PVConservancy

The mean coefficient of conservatism for Pleasant Valley Conservancy is 5.1, which is an impressively high value for a landscape that has been under restoration for such a short period of time. Using these data, the Floristic Quality Index calculated using the Swink and Wilhelm formula, is 91.3, again, an impressively high number. (According to an assessment by Michigan workers, an FQI greater than 50 represents an area of high conservatism and an area with an FQI greater than 35 is considered floristically important in the state.)

Obviously, a high FQI depends on the presence of species with high C values. Such plants show strong fidelity to specific habitats. Such fidelity goes hand-in-hand with rarity. However, a high C value does not necessarily mean that the species is "endangered" or "threatened". This depends on the commoness of the required habitat of a plant with high C value. For instance, Lithospermum canescens has a C value of 10 but is not endangered or threatened, because its preferred habitat, dry prairie remnants, is fairly common in the state.

 

Floristic Quality Index for Each Management Unit

Name FQI Acreage Total species Present status of unit
Unit 6 63 4.48 153 Upper (Bur oak savanna) Lower (Prairie remnant)
Unit 11A 61 5.17 119 Prairie remnant and bur oak savana
Toby's Prairie 61 3.63 126 Dry-mesic prairie (partially remnant; mostly planted)
Unit 10 60 2.9 136 Bur oak savanna
Unit 12A 59 5.95 138 White oak savanna
Valley Prairie 58 3.85 130 Dry, mesic, and wet-mesic prairie (planted)
Pocket Prairie 57 4.5 104 Dry, mesic, and wet-mesic prairie (planted)
Unit 7 56 1.58 117 Upper (Bur oak savanna) Lower (Prairie remnant)
Unit 3 56 1.03 105 Prairie remnant
Crane Prairie 55 2.6 130 Dry, dry-mesic, and mesic prairie (planted)
Unit 8 54 1.3 102 Bur oak savanna
Unit 12B 54 0.98 114 White oak savanna
Unit 5 52.5 1.61 105 Bur oak savanna
Unit 2 52 1.6 89 Prairie remnant
East Basin 51.5 4.4 100 Dry-mesic, mesic, and wet-mesic prairie (planted)
Ridge Prairie 51 1.67 100 Dry-mesic prairie (planted)
Unit 23 51 0.38 93 Bur oak savanna
Unit 19C 48 1.13 71 Black/bur oak savanna
Unit 21 47 3.38 75 White oak woodland
Triangle 47 0.55 81 Hill's oak savanna
Unit 20 combined 46 3.35 86 Woods and prairie mix
Barn 46 0.48 87 Wet mesic prairie (planted)
Unit 9 45 1.82 82 Bur oak savanna
Cabin Prairie 45 0.54 83 Mesic prairie (planted)
Unit 1 44 1.18 61 Prairie remnant
Unit 11D 43 4 74 White oak savanna
Unit 4 41 0.32 48 Prairie remnant
Unit 19A 40.8 0.33 69 Bur oak savanna
Unit 19B 38 1.64 51 Bur oak savanna
Unit 19D 35 1.05 30 Bur oak/black oak savanna
Unit 19E 34 1.47 37 White oak savana

 

The table below lists the species found at Pleasant Valley Conservancy in order of their C value, from high to low, based on data from 4 years.

Coefficient of Conservatism for Plant Species

Latin name
Common name
C value
Carex prairea
Prairie sedge
10
Lithospermum canescens
Hoary puccoon
10
Panicum leibergii
Prairie panic grass
10
Sporobolus heterolepis
Prairie dropseed
10
Asclepias purpurascens
Purple milkweed
9
Asclepias viridiflora
Short green milkweed
9
Aster prenanthoides
Crooked aster
9
Ceanothus americanus
New Jersey tea
9
Cypripedium parviflorum var pubescens
Large yellow lady-slipper
9
Eupatorium sessilifolium
Woodland boneset
9
Liatris cylindracea
Dwarf blazing star
9
Stipa sp
Needle grass
9
Viola pedatifida
Prairie violet
9
Aster sericeus
Silky aster
8
Astragalus canadensis
Canadian milkvetch
8
Aureolaria grandiflora
Yellow false foxglove
8
Baptisia alba
White wild indigo
8
Bromus kalmii
Prairie brome
8
Carex eburnii
Bristle-leaf sedge
8
Cirsium muticum
Swamp thistle
8
Coreopsis palmata
Prairie tickseed
8
Dalea candida
White prairie clover
8
Eryngium yuccifolium
Rattlesnake master
8
Hasteola suaveolens
Sweet Indian plantain
8
Hypoxis hirsuta
Yellow star-grass
8
Lithospermum incisum
Fringed puccoon
8
Oxalis violacea
Violet wood-sorrel
8
Parthenium integrifolium
Wild quinine
8
Pedicularis canadensis
Wood betony
8
Pedicularis lanceolata
Lousewort
8
Pediomelum esculentum
Prairie turnip
8
Polygala senega
Seneca snakeroot
8
Silphium laciniatum
Compass plant
8
Solidago ptarmicoides
Prairie goldenrod
8
Sphenopholis obtusata
Wedge grass
8
Symplocarpus foetidus
Skunk cabbage
8
Viburnum prunifolium
Black haw
8
Actaea rubra
Red baneberry
7
Allium cernuum
Nodding wild onion
7
Amorpha canescens
Lead-plant
7
Arabis canadensis
Sickle pod
7
Aralia racemosa
Spikenard
7
Arenaria stricta
Sandwort
7
Asclepias exaltata
Poke milkweed
7
Bouteloua hirsuta
Hairy gramma grass
7
Bromus ciliatus
Fringed brome
7
Campanula aparinoides
Marsh bellflower
7
Carex grayi
Bur sedge
7
Carex stricta
Tussock sedge
7
Carex trichocarpa
Hairy-fruit sedge
7
Chelone glabra
Turtlehead
7
Cornus rugosa
Round-leaved dogwood
7
Dalea purpureum
Purple prairie clover
7
Desmodium illinoense
Illinois tick-trefoil
7
Dicentra cucullaria
Dutchman's breeches
7
Dodecatheon meadia
Shooting star
7
Echinacea pallida
Pale purple coneflower
7
Galium lanceolatum
Lance-leaved bedstraw
7
Gentiana alba
Cream gentian
7
Gentianella quinquefolia
Stiff gentian
7
Geum triflorum
Prairie smoke
7
Goodyera pubescens
Rattlesnake plantain
7
Helianthus decapetalus
Pale sunflower
7
Helianthus pauciflorus
Prairie sunflower
7
Heuchera richardsonii
Prairie alum-root
7
Koeleria macrantha
June grass
7
Liatris pycnostachya
Prairie blazing star
7
Linum medium texanum
Small yellow flax
7
Lobelia cardinalis
Cardinal flower
7
Panicum latifolium
Broad-leaved panic-grass
7
Potentilla arguta
Prairie cinquefoil
7
Quercus alba
White oak
7
Saxifraga pensylvanica
Swamp saxifrage
7
Scutellaria parvula
Leonard's skullcap
7
Silphium terebinthinaceum
Prairie dock
7
Sisyrinchium campestre
Blue-eyed grass
7
Solidago missouriensis
Missouri goldenrod
7
Taenidia integerrima
Yellow pimpernel
7
Thalictrum dioicum
Early meadow-rue
7
Uvularia grandiflora
Bellwort
7
Viburnum acerifolium
Maple-leaved viburnum
7
Viola canadensis
Tall white violet
7
Viola pedata
Bird's foot violet
7
Zizia aurea
Golden Alexander
7
Actaea alba
White baneberry
6
Amelanchier arborea
Juneberry
6
Anemone cylindrica
Thimbleweed
6
Anemone quinquefolia
Wood anemone
6
Angelica atropurpurea
Great angelica
6
Arabis divaricarpa
Rock cress
6
Aralia nudicaulis
Wild sarsaparilla
6
Asclepias tuberosa
Butterfly weed
6
Aster firmus
Shining aster
6
Aster laevis
Smooth blue aster
6
Aster umbellatus
Flat-top aster
6
Bouteloua curtipendula
Side oats grama
6
Bromus latiglumis
Ear-leaved brome
6
Caltha palustris
Marsh marigold
6
Cardamine bulbosa
Spring cress
6
Carex lacustris
Common lake sedge
6
Cicuta maculata
Water-hemlock
6
Cirsium altissimum
Woodland thistle
6
Coeloglossum viride
Long-bracted green orchid
6
Desmodium glutinosum
Pointed tick-trefoil
6
Elymus hystrix
Bottlebrush grass
6
Elymus riparius
Riverbank wild rye
6
Elymus villosus
Silky wild rye
6
Elymus virginicus
Virginia wild rye
6
Eupatorium perfoliatum
Common boneset
6
Eupatorium purpureum
Purple joe-pye weed
6
Galearis spectabilis
Showy orchis
6
Galium concinnum
Shining bedstraw
6
Gentiana andrewsii
Bottle gentian
6
Helianthemum canadense
Common rockrose
6
Hieracium longipilum
Prairie hawkweed
6
Hypericum pyramidatum
Great St. John's wort
6
Lilium michiganense
Turk's cap lily
6
Lobelia spicata
Pale spiked lobelia
6
Lupinus perennis
Wild lupine
6
Lysimachia quadrifolia
Whorled loosestrife
6
Napaea dioica
Glade mallow
6
Orobanche uniflora
Cancer root
6
Oxypolis rigidior
Cowbane
6
Polemonium reptans
Jacob's ladder
6
Polygonum sagitattum
Arrow-leaved tear-thumb
6
Pycnanthemum virginianum
Common mountain mint
6
Ranunculus fascicularis
Early buttercup
6
Ranunculus hispidus
Swamp buttercup
6
Rudbeckia laciniata
Cut-leaved coneflower
6
Salix humilis
Prairie willow
6
Sanguinaria canadensis
Bloodroot
6
Senecio plattensis
Prairie ragwort
6
Silphium integrifolium
Rosinweed
6
Solidago flexicaulis
Zig-zag goldenrod
6
Trillium grandiflorum
Large-flowered trillium
6
Veronicastrum virginicum
Culver's root
6
Agastache nepetoides
Yellow giant hyssop
5
Amphicarpaea bracteata
Hog peanut
5
Anemone virginiana
Tall anemone
5
Aquilegia canadensis
Wild columbine
5
Arisaema triphyllum
Jack-in-the-pulpit
5
Asclepias incarnata
Swamp milkweed
5
Aster oolentangiensis
Sky-blue aster
5
Aster puniceus
Swamp aster
5
Calamagrostis canadensis
Blue-joint grass
5
Campanula rotundifolia
Harebell
5
Carya ovata
Shagbark hickory
5
Corylus americana
American hazelnut
5
Galium boreale
Northern bedstraw
5
Galium tinctorium
Stiff bedstraw
5
Helianthus divaricatus
Woodland sunflower
5
Heliopsis helianthoides
Ox-eye sunflower
5
Hieracium kalmii
Canada hawkweed
5
Iris virginica
Wild iris
5
Kuhnia eupatorioides
False boneset
5
Lathyrus palustris
Marsh pea
5
Lespedeza capitata
Round-headed bush clover
5
Liatris aspera
Rough blazing star
5
Liparis lilifolia
Purple twayblade
5
Lobelia siphilitica
Great blue lobelia
5
Lysimachia ciliata
Fringed loosestrife
5
Maianthemum canadense
Canada Mayflower
5
Osmorhiza claytoni
Hairy sweet cicely
5
Parthenocissus quinquefolia
Virginia creeper
5
Phryma leptostachya
Lopseed
5
Polygala sanguinea
Field milkwort
5
Polygonum punctatum
Smartweed
5
Prenanthes alba
Lion's foot
5
Quercus macrocarpa
Bur oak
5
Quercus velutina
Black oak
5
Ranunculus recurvatus
Hooked buttercup
5
Sanicula marilandica
Black snakeroot
5
Scutellaria galericulata
Marsh skullcap
5
Smilacina racemosa
False Solomon's seal
5
Smilacina stellata
Starry false Solomon's seal
5
Smilax herbacea
Carrion flower
5
Smilax illinoensis
Greenbrier
5
Solidago rigida
Stiff goldenrod
5
Solidago speciosa
Showy goldenrod
5
Solidago ulmifolia
Elm-leaved goldenrod
5
Sorghastrum nutans
Indian grass
5
Spartina pectinata
Prairie cord grass
5
Stachys palustris
Hedge-nettle
5
Stellaria longifolia
Stitchwort
5
Tradescantia ohiensis
Common spiderwort
5
Triosteum perfoliatum
Tinker's weed
5
Vernonia fasciculata
Common ironweed
5
Viola pubescens
Yellow wood violet
5
Agastache scrophulariaefolia
Purple giant hyssop
4
Allium canadense
Wild onion
4
Andropogon gerardii
Big bluestem
4
Anemone canadensis
Meadow anemone
4
Arabis lyrata
Sand cress
4
Arnoglossum (Cacalia) atriplicifol
Pale Indian plantain
4
Aster ericoides
Heath aster
4
Aster lanceolatus
Panciled aster
4
Bidens cernuus
Nodding beggar's tick
4
Campanula americana
Tall bellflower
4
Carex bebbii
Bebb's oval sedge
4
Carex pellita
Broad-leaved wooly sedge
4
Carex rosea
Rosy sedge
4
Celtis occidentalis
Hackberry
4
Cirsium discolor
Pasture thistle
4
Clematis virginiana
Virgins bower
4
Cryptotaenia canadensis
Honewort
4
Desmodium canadense
Showy tick-trefoil
4
Dioscorea villosa
Wild yam
4
Elymus canadensis
Canada wild rye
4
Erigeron pulchellus
Robin's plantain
4
Eupatorium altissimum
Tall boneset
4
Eupatorium maculatum
Spotted joe-pye weed
4
Euphorbia corollata
Flowering spurge
4
Euthamia graminifolia
Grass-leaved goldenrod
4
Festuca subverticillata
Nodding fescue
4
Geranium maculatum
Wild geranium
4
Glyceria stricta
Fowl manna grass
4
Helenium autumnale
Sneezeweed
4
Helianthus strumosus
Pale-leaved woodland sunflower
4
Hydrophyllum virginianum
Virginia waterleaf
4
Hypericum punctatum
Dotted St. John's wort
4
Krigia biflora
False dandelion
4
Laportea canadensis
Wood-nettle
4
Lycopus americanus
Common water-horehound
4
Osmorhiza longistylis
Smooth sweet cicely
4
Panicum oligosanthes
Few-flowered panic-grass
4
Panicum virgatum
Switch grass
4
Penstemon grandiflorus
Large-flowered beard-tongue
4
Physalis virginiana
Lance-leaved ground-cherry
4
Podophyllum peltatum
May-apple
4
Polygonatum biflorum
Smooth Solomon's seal
4
Ratibida pinnata
Yellow coneflower
4
Ribes americanum
Black currant
4
Rosa sp.
Rose
4
Rudbeckia hirta
Black-eyed Susan
4
Rudbeckia triloba
Brown-eyed Susan
4
Schizachyrium scoparium
Little bluestem
4
Scirpus cyperinus
Wool-grass
4
Scrophularia lanceolata
Early figwort
4
Scrophularia marilandica
Late figwort
4
Senecio pauperculus
Balsam ragwort
4
Silphium perfoliatum
Cup plant
4
Solidago juncea
Early goldenrod
4
Solidago nemoralis
Gray goldenrod
4
Teucrium canadense
Germander
4
Thalictrum dasycarpum
Purple meadow-rue
4
Toxicodendron radicans
Poison ivy
4
Viburnum lentago
Nannyberry
4
Vicia americana
American vetch
4
Anaphalis margaritacea
Pearly everlasting
3
Antennaria neglecta
Field pussytoes
3
Antennaria plantaginifolia
Plantain-leaved pussytoes
3
Apocynum cannabinum
Indian hemp
3
Apocynum sibiricum
Clasping dogbane
3
Aster lateriflorus
Calico aster
3
Aster novae-angliae
New England aster
3
Aster sagittifolius
Arrow-leaved aster
3
Carex blanda
Common wood sedge
3
Carex hystericina
Porcupine sedge
3
Carex pensylvanica
Pennsylvania sedge
3
Celastrus scandens
Climbing bittersweet
3
Epilobium coloratum
Cinnamon willow-herb
3
Eragrostis spectabilis
Purple Lovegrass
3
Geum aleppicum
Yellow avens
3
Hackelia virginiana
Stickseed
3
Heracleum lanatum
Cow parsnip
3
Lactuca biennis
Tall blue lettuce
3
Leersia oryzoides
Rice cut grass
3
Mentha arvensis
Wild mint
3
Monarda fistulosa
Wild bergamot
3
Monarda punctata
Horse mint
3
Prunus americana
Wild plum
3
Prunus serotina
Wild black cherry
3
Prunus virginiana
Choke cherry
3
Ribes cynosbati
Gooseberry
3
Sambucus canadensis
Elderberry
3
Solidago gigantea
Late goldenrod
3
Triodanis perfoliata
Venus looking glass
3
Verbena hastata
Blue vervain
3
Verbena stricta
Hoary vervain
3
Viola soraria
Door-yard violet
3
Zanthoxylum americanum
Prickly ash
3
Agrimonia gryposepala
Tall agrimony
2
Apocynum androsaemifolium
Spreading dogbane
2
Asclepias verticillata
Whorled milkweed
2
Carex stipata
Common fox sedge
2
Carex vulpinoidea
Brown fox sedge
2
Circaea lutetiana
Enchanter's nightshade
2
Cornus racemosa
Gray dogwood
2
Echinocystis lobata
Wild cucumber
2
Erechtites hieracifolia
Fireweed
2
Erigeron philadelphicus
Marsh fleabane
2
Erigeron strigosus
Daisy fleabane
2
Galium aparine
Annual bedstraw
2
Gaura biennis
Biennial gaura
2
Geum canadense
White avens
2
Helianthus grosseserratus
Saw-tooth sunflower
2
Helianthus tuberosus
Jerusalem artichoke
2
Lactuca canadensis
Tall lettuce
2
Lobelia inflata
Indian tobacco
2
Potentilla simplex
Old-field cinquefoil
2
Rhus glabra
Smooth sumac
2
Silene antirrhina
Sleepy catchfly
2
Verbena urticifolia
White vervain
2
Achillea millefolium
Yarrow
1
Asclepias syriaca
Common milkweed
1
Aster pilosus
Hairy aster
1
Eupatorium rugosum
White snakeroot
1
Fragaria virginiana
Wild strawberry
1
Oenothera biennis
Common evening-primrose
1
Polygonum pensylvanicum
Lady's thumb
1
Prunella sp.
Self-heal
1
Ranunculus abortivus
Small-flowered buttercup
1
Solidago canadensis
Common goldenrod
1
Typha latifolia
Cattail
1
Urtica sp.
Nettle
1
Oxalis stricta
Yellow wood-sorrel
0
Potentilla norvegica
Rough cinquefoil
0
 
 
C = 5.1
Median C = 5
FQI=91.2
 
319 species out of 401 in 2005 database